His scope of work in orthopaedics includes lower back, total hip and knee replacement, hand and feet. He also performs arthroscopic procedures and surgery in fracture cases.

Dr Payachapan graduated from Siriraj Medical School in Bangkok then completed his orthopaedic training at Winthrop University Hospital, Long Island New York. He was certified by the American Board of Orthopaedic Surgeons in 1976. He was the Director of the Orthopaedic Department of Bangkok Hospital from 1982 to 2005. He also worked in the trauma centre at the Good Samaritan Hospital Long Island until 2012.

He then decided to move to Hua Hin and was appointed as the Director of Orthopaedic Surgery. Dr Payachapan is also a Member of the American Academy of Orthopaedic Surgeons (AAOS).

Hua Hin Today is a monthly, principally English language newspaper, published in Hua Hin, Thailand. The paper was established in 2003. The paper is distributed throughout the Provinces of Phetchaburi and Prachuap Khiri Khan with a focus on the towns of Hua Hin, Cha-Am and Pranburi. It is the only English language newspaper in this region.